Phosphonate/phosphinate containing heribicdal compositions and the use thereof

ABSTRACT

A herbicidal composition which comprises a phosphonate or phosphinate of the formula ##STR1## where R and R 1 , which may be the same or different, each represent straight or branch-chained alkyl of 1 to 12 carbon atoms, and x and y are each 1 or 2, the sum of x an y being 3; and phenmedipham, desmedipham, metamitron, lenacil, ethofumesate or chloridazon in association with a suitable carrier and/or surface active agent, and a method of combating weeds.

This invention concerns new herbicidal compositions and methods of combating weeds.

PRIOR ART

U.S. Pat. No 2927014 discloses phosphonates and phosphinates having herbicidal activity. We have now found that combinations of certain alkyl substituted phosphonates and phosphinates according to the U.S. Patent with certain known sugar beet herbicides are surprisingly beneficial and synergistic.

DESCRIPTION

In one aspect, the invention provides a herbicidal composition comprising:

(a) at least one phosphonate or phosphinate of the formula: ##STR2## where R and R¹, which may be the same or different, each represent straight or branch-chained alkyl of 1 to 12 carbon atoms, and x and y are each 1 or 2, the sum of x and y being-3; and

(b) at least one compound selected from phenmedipham, desmedipham, metamitron, lenacil, ethofumesate and chloridazon, or a combination of 2 and more

in association with a suitable carrier and/or surface active agent.

In another aspect, the invention provides a method of combating weeds which comprises applying to a locus infested or liable to be infested therewith, an effective amount of the two components (a) and (b).

Preferred compounds of formula I are those wherein R and R^(l) each represent 2-ethylhexyl or dodecyl, especially 0,0-bis(2-ethylhexyl) (2-ethylhexyl) phosphonate.

The ratio by weight of (a) to (b) employed is preferably from 10:1 to 1:10, especially from 5:1 to 1:5.

The compositions of the invention are herbicidally-active against a wide range of broad-leaved and grass weeds, including Alopecurus, Echinochloa, Setaria, Amaranthus, Atriplex, Centaurea, Galium, Matricaria, Mercurialis, Polygonum and Stellaria species, but are comparatively safe to certain crop species, particularly beets. They may thus be of use as herbicides, and especially as selective herbicides, particularly in the control of a range of weeds in such crops.

The compositions of the invention usually contain from 0.01 to 99% by weight of the present compounds, and are normally produced initially as concentrates containing from 0.5 to 99%, preferably from 0.5 to 85%, and especially from 10 to 50% by weight thereof. Such concentrates are diluted if necessary before application to the locus to be treated such that the active ingredient comprises from 0.01 to 5% by weight of the formulation applied.

The carrier may be water, in which case an organic solvent may also be present, though this is not usually employed. A flowable suspension concentrate may be formed by grinding the compound with water, a wetting agent and a suspending agent,e.g. xanthan gum.

The carrier may alternatively be a water immiscible organic Solvent, e.g. a hydrocarbon which boils within the range 130°-270° C., e.g. xylene, in which the compound is dissolved or suspended. An emulsifiable concentrate containing a water immiscible solvent may be formed with a surface active agent so that the concentrate acts as a self-emulsifiable oil on admixture with water.

The carrier may alternatively be a water-miscible organic solvent e.g. 2-methoxy ethanol, methanol, propylene glycol, diethylene glycol, diethylene glycol monoethyl ether, methylformamide or dimethylformamide.

The carrier may alternatively be a solid, which may be finely divided or granular. Examples of suitable solids are limestone, clays, sand, mica, chalk, attapulgite, diatomite, perlite, sepiolite, silicas, silicates, lignosulphonates and solid fertilizers. The carrier can be of natural or synthetic origin or can be modified natural material.

Wettable powders soluble or dispersible in water may be formed by admixing the compound in particulate form with a particulate carrier or spraying molten compound on to the particulate carrier, admixing a wetting agent and a dispersing agent and finely grinding the whole powder mixture.

An aerosol composition may be formed by admixing the compound with a propellant, e.g. a polyhalogenated alkane such as dichlorofluoromethane, and suitably also with a solvent.

The term `surface active agent` is used in the broad sense to include materials variously called emulsifying agents, dispersing agents and wetting agents. Such agents are well known in the art.

The surface active agents used may comprise anionic surface active agents, for example mono- or di-esters of phosphoric acid with a fatty alcohol ethoxylate, or salts of such esters, fatty alcohol sulphates such as sodium dodecyl sulphate, ethoxylated fatty alcohol sulphates, ethoxylated alkylphenol sulphates, lignin sulphates, petroleum sulphonates, alkylaryl sulphonates such as alkyl-benzene sulphonates or lower alkylnaphthalene sulphonates, salts of sulphonated naphthaleneformaldehyde condensates, salts of sulphonated phenolformaldehyde condensates, or more complex sulphonates such as the amide sulphonates, e.g. the sulphonated condensation product of oleic acid and N-methyl taurine or the dialkyl sulfosuccinates e.g. the sodium sulphonate of dioctyl succinate.

The surface active agents may also comprise non-ionic agents, for example condensation products or fatty acid esters, fatty alcohols, fatty acid amides or alkyl-substitutedphenols with ethylene oxide, fatty esters of polyhydric alcohol ethers e.g. sorbitan fatty acid esters, condensation products of such esters with ethylene oxide e.g. polyoxyethylene sorbitan fatty acid esters, block copolymers of ethylene oxide and propylene oxide, acetylenic glycols such as 2,4,7,9-tetramethyl-5-decyn-4,7-diol, or ethoxylated acetylenic glycols. The surface active agents may also comprise cationic agents, for example alkyl- and/or aryl-substituted quaternary ammonium compounds such as cetyl trimethylammonium bromide, or ethoxylated tertiary fatty amines.

Preferred surface active agents include ethoxylated fatty alcohol sulphates, lignin sulphonates, alkyl-aryl sulphonates,salts of sulphonated naphthaleneformaldehyde condensates, salts of sulphonated phenolformaldehyde condensates, sodium oleoyl N-methyltauride, dialkyl sulfosuccinates, alkyl phenol ethoxylates, and fatty alkyl ethoxylates.

If the components (a) and (b) are applied sequentially, they may each be applied in a composition analogous to those described above.

If desired, the compositions may contain one or more further active ingredients, eg herbicides, fungicides or insecticides in addition to components (a) and (b).

The present compound may be applied to plants, the soil, land or aquatic areas, and particularly to a locus at which a crop is growing. The method is particularly active post-emergence.

In the present method, the amount of (a) applied is preferably from 0.01 to 1 kg/ha, preferably from 0.05 to 0.25 kg/ha. The amount of (b) applied is preferably from 0.01 to 2 kg/ha, preferably from 0.05 to 0.5 kg/ha. The amount of (a) and (b) in total applied is preferably from 0.3 to 3 kg/ha.

EXAMPLE

The invention is illustrated by the following Examples in which the compounds employed are identified as follows:

I 0,0-bis (2-ethylhexyl) (2-ethylhexyl)phosphonate

II phenmedipham

III metamitron

IV lenacil

V chloridazon

V desmedipham

and plant species are identified as follows:

a Alopecurus myosuroides

b Amaranthus retroflexus

c Atriplex hortensis

d Beta vulgaris altissima

e Beta vulgaris crassa

f Beta vulgaris conditiva

g Centaurea cyanus

h Echinochloa crus-galli

i Galium aparine

j Matricaria chamomilla

k Mercurialis annua

l Setaria italica

m Stellaria media.

All rates of application are given as grams active ingredient per hectare (g a.i./ha).

Example 1

The compounds listed below were applied alone and in combination at the rates indicated to beets and weed seedlings grown in a greenhouse. Herbicidal effects were noted 6-10 days after application on a scale of from 0 (no effect) to 10 (complete kill).

    ______________________________________                                         Compds  Rate       a     i     j   k     d   f                                 ______________________________________                                         I        300       0.5   0.5   0.0 0.2   0.5 1.0                                       1000       1.0   2.0   0.5 0.5   2.2 3.5                               I + II   250 + 50  3.0   4.5   1.5 2.5   0.8 0.5                                        200 + 100 4.5   7.0   4.0 1.5   0.8 0.5                                        150 + 150 4.5   6.5   4.5 1.0   0.8 0.0                                        100 + 200 4.0   6.5   4.5 2.0   1.0 0.0                                        50 + 250  3.5   4.5   4.5 2.0   0.8 0.0                               II       300       3.5   5.0   3.5 0.5   0.5 0.5                                       1000       5.0   8.0   6.0 2.5   0.5 2.0                               ______________________________________                                         Compds  Rate      a     b    c   g    i   j    m   d                           ______________________________________                                         I        300      0.5   3.0  1.0 1.0  0.5 0.0  1.0 0.5                                 1000      1.0   3.5  2.5 1.5  2.0 0.5  1.5 2.2                         I + III  250 + 50 1.0   3.0  3.0 2.0  2.0 3.5  2.0 1.2                                  200 + 100                                                                               1.0   4.5  3.5 2.0  3.0 4.5  2.0 0.5                                  150 + 150                                                                               2.0   4.5  4.5 1.5  4.0 5.0  2.0 0.8                                  100 + 200                                                                               2.0   5.0  4.0 1.5  2.5 4.0  2.0 0.5                                  50 + 250 1.5   4.0  3.0 1.0  2.0 3.0  2.5 0.4                         III      300      0.5   2.5  0.5 1.5  0.5 3.0  0.0 0.2                                 1000      4.0   3.5  2.5 2.5  1.5 6.0  0.5 0.2                         ______________________________________                                    

Example 2

The compounds listed below were applied alone and in combination at the rates indicated to beets and weed seedlings grown in a greenhouse. The plants were harvested 8 to 14 days after treatment, and the harvested weights were measured. The percentage weight reductions relative to an untreated control were as follows:

    ______________________________________                                         Compds Rate      a      g   i     k   d    e    f                              ______________________________________                                         I       300       5      0  32     8  5    2    0                                     1000      12      4  42     0  12   5    0                              I + II  250 + 50 37     19  80     7  2    3    2                                      200 + 100                                                                               59     22  86    25  1    8    0                                      150 + 150                                                                               59     28  87     7  5    8    0                                      100 + 200                                                                               55     25  85    26  4    10   0                                      50 + 250 57     22  85    48  0    6    1                              II      300      52     23  79    16  0    3    0                                     1000      67     39  92    29  4    24   16                             ______________________________________                                         Compds Rate      b     c    g   i    m   d    e    f                           ______________________________________                                         I       300      12     2    0  32    4  5    2    0                                  1000      23    39    4  42   14  12   5    0                           I + III                                                                                250 + 50 27    53   10  55   36  4    4    0                                   200 + 100                                                                               41    62   15  69   50  0    7    0                                   150 + 150                                                                               46    73   19  70   54  0    0    6                                   100 + 200                                                                               50    69   19  69   54  0    2    0                                   50 + 250 47    53   17  61   46  0    1    0                           III     300      18     6    7  45   24  0    3    0                                  1000      51    55   23  70   53  0    0    0                           Control           0     0    0   0   0   0    0    0                           ______________________________________                                         Compds Rate      c      h   i     l   m     d    f                             ______________________________________                                         I       300       2      0  32    23   4    5    0                                    1000      39     20  42    46  14    12   0                             I + IV  250 + 50  4     21  36    27   1    0    0                                     200 + 100                                                                               12     25  45    41  14    3    0                                     150 + 150                                                                               37     28  54    41  16    12   4                                     100 + 200                                                                               57     27  58    46  17    13   4                                     50 + 250 40     26  50    41  26    4    5                             IV      300       0     16  17    25   3    0    0                                    1000      15     32  34    33  13    0    0                             Control           0      0   0     0   0    0    0                             ______________________________________                                         Compds Rate      b     c    g   h    i   l    m   f                            ______________________________________                                         I       600      15    20    4  12   15  26    8  0                                   2000      30    70   25  57   14  32   33  5                            I + V   500 + 100                                                                               57    81   17  48   69  54   40  6                                    400 + 200                                                                               74    83   16  49   74  55   43  11                                   300 + 300                                                                               65    82   17  57   76  56   50  7                                    200 + 400                                                                               68    83   18  52   74  47   41  9                                    100 + 500                                                                               46    77   17  50   64  41   35  2                            V       600      18    22    3  35   30  23   15  0                                   2000      42    49   22  59   45  41   39  2                            Control           0     0    0   0    0   0    0  0                            ______________________________________                                         Compds Rate      a     c     g   i     j   m     f                             ______________________________________                                         I       500      10     0     0   0    13   6     7                                   1000      31    50     8   0    20  56    27                            I + VI  300 + 200                                                                               50    73    46  62    59  78     0                                    600 + 400                                                                               66    86    67  81    76  89    30                            VI      500      28    36    45  51    60  65     2                                   1000      55    73    58  75    68  84    32                            Control           0     0     0   0     0   0     0                            ______________________________________                                         Compds Rate      a     c     g   j     h   i     e                             ______________________________________                                         I      680       14    31     0  13    19   0    27                            I + II 680 + 450 55    71    57  79    71  90    13                            II     450       18     1    16  48    18  40     0                            Control           0     0     0   0     0   0     0                            ______________________________________                                         Compds   Rate          a     h   i   j    m   d                                ______________________________________                                         I         300           0     0   0   0    4  5                                         1000          19    27  17   6    8  10                               I + II + VI                                                                              193 + 53.5 + 53.5                                                                           35    85  79  50   33  0                                          430 + 120 + 120                                                                             46    86  90  70   43  9                                II + VI   150 + 150    18    72  54  32   18  0                                          335 + 335    41    79  80  53   28  2                                Control                 0     0   0   0    0  0                                ______________________________________                                    

Example 3:

The compounds listed below were applied alone and combination at the rates indicated to beets and weed seedlings grown in a greenhouse. Herbicidal effects were noted 6-10 days after application on a scale from 0 (no effect) to 10 (complete kill). Results were obtained as follows:

    ______________________________________                                         a)     with compound VII   g a.i./ha m                                         ______________________________________                                                ethofumesate VII    600       4.0                                              VII                 500       5.0                                              +                    +                                                         diethylmethylphosphonate                                                                           100                                                        (ZK 146 953) (VIII)                                                            VII + VIII          400       4.5                                                                   +                                                                             200                                                        VIII                600       0.1                                              VII                 500       4.5                                              +                    +                                                         diethylethylphosphonate                                                                            100                                                        (ZK 53 491) (IX)                                                               VII + IX            400       4.5                                                                   +                                                                             200                                                        IX                  600       0.2                                       ______________________________________                                         b)     with compound II    g a.i./ha j                                         ______________________________________                                                II                  300       3.5                                              II +                100 + 200 6.5                                              dipentylpentylphosphonate                                                                          150 + 150 4.0                                              (ZK 148 236) (X)                                                               X                   300       0                                                II +                200 + 100 5                                                dibutylbutylphosphonate                                                                            100 + 200 5.5                                              (ZK 147 326) (XI)                                                              (XI)                300       0.5                                              II +                200 + 100 5                                                diisopropylallylphosphonate                                                                        100 + 200 5.5                                              (ZK 147 327) (XII)                                                             XII                 300       0                                                II +                200 + 100 4.0                                              diisoproyplmethylphosphonate                                                                       100 + 200 4.5                                              (ZK 146 952) (XIII)                                                            XIII                300       0                                         ______________________________________                                     

I claim:
 1. A herbicidal composition comprising a synergistic combination of:(a) at least one phosphonate or phosphinate of the formula: ##STR3## where R and R', which may be the same or different, each represent straight or branch-chained alkyl of 1 to 12 carbon atoms, and x and y are each 1 or 2, the sum of x and y being 3; and (b) at least one compound selected from phenmedipham, desmedipham, metamitron, lenacil, ethofumesate and chloridazon, the ratio by weight of component (a) to component (b) being from 1:10 to 10:1; in association with a suitable carrier and/or surface active agent.
 2. A composition according to claim 1 in which each R and R¹ group in the compound of formula I is 2-ethylhexyl or dodecyl.
 3. A composition according to claim 1 in which x in the compound of formula I is
 2. 4. A composition according to claim 1 in which the ratio by weight of component (a) to component (b) is from 1:5 to 5:1.
 5. A method of combating weeds which comprises applying to a locus infested or liable to be infested therewith, and effective amount of the two components (a) and (b) as defined in claim 1 the ratio by weight of component (a) to component (b) being from 1:10 to 10:1, and in which the amount of (a) applied is 0.01 to 1 kg/ha.
 6. A method according to claim 5 in which the amount of component (a) applied is from 0.05 to 0.25 kg/ha.
 7. A method according to claim 5 in which the amount of (b) applied is from 0.01 to 2 kg/ha.
 8. A method according to claim 5 in which the total amount of components (a) and (b) applied is from 0.03 to 3 kg/ha.
 9. A method according to claim 5 in which each R and R' group in the compound of formula I is 2-ethylhexyl or dodecyl.
 10. A method according to claim 9 in which compound I is a O, O-bis(2-ethylhexyl) (2-ethylhexyl) phosphonate.
 11. A composition according to claim 2 in which the compound of formula I is O,O-bis(2-ethylhexyl) (2-ethylhexyl) phosphonate. 